Have a very simple messaging site I want to build. It is like twitter.com except I want something people can use for their own websites to communicate with one another. To try a similar service: http://tinyurl.com/56jyac

Here is the template for what I want, i have the css ready for you to integrate.
http://www.box.net/shared/static/qq8ta6a6v1.jpg

I would like to use php and mysql and have very well organized code because I intend to release this as an open source app.

Features
-user login, very basic profile
-Discussions (each button at the top is a different discussion) different discussions may have different sets of users)
-archive (shows daily chats)
-search (searches any text stored in archive by day, month or all time) by default search should search just the messages in that discussion page
- click user name to get history of their messages and user profile
- main messaging functionality
-password protection so people typing the address cant search or see messages unless they are part of the group
- easy install wizard like install.php that people can use to very easily install this on other servers. It should work like a wordpress.org install, something automatic and simple.

There is an open source project for micro blogging that you are welcome to take code from if it is useful.
http://laconi.ca/trac/